Dengue Virus Genome Uncoating Requires Ubiquitination

The process of genome release or uncoating after viral entry is one of the least-studied steps in the flavivirus life cycle. Flaviviruses are mainly arthropod-borne viruses, including emerging and reemerging pathogens such as dengue, Zika, and West Nile viruses. Currently, dengue virus is one of the most significant human viral pathogens transmitted by mosquitoes and is responsible for about 390 million infections every year around the world. Here, we examined for the first time molecular aspects of dengue virus genome uncoating. We followed the fate of the capsid protein and RNA genome early during infection and found that capsid is degraded after viral internalization by the host ubiquitin-proteasome system. However, proteasome activity and capsid degradation were not necessary to free the genome for initial viral translation. Unexpectedly, genome uncoating was blocked by inhibiting ubiquitination. Using different assays to bypass entry and evaluate the first rounds of viral translation, a narrow window of time during infection that requires ubiquitination but not proteasome activity was identified. In this regard, ubiquitin E1-activating enzyme inhibition was sufficient to stabilize the incoming viral genome in the cytoplasm of infected cells, causing its retention in either endosomes or nucleocapsids. Our data support a model in which dengue virus genome uncoating requires a nondegradative ubiquitination step, providing new insights into this crucial but understudied viral process. IMPORTANCE: Dengue is the most significant arthropod-borne viral infection in humans. Although the number of cases increases every year, there are no approved therapeutics available for the treatment of dengue infection, and many basic aspects of the viral biology remain elusive. After entry, the viral membrane must fuse with the endosomal membrane to deliver the viral genome into the cytoplasm for translation and replication. A great deal of information has been obtained in the last decade regarding molecular aspects of the fusion step, but little is known about the events that follow this process, which leads to viral RNA release from the nucleocapsid. Here, we investigated the fate of nucleocapsid components (capsid protein and viral genome) during the infection process and found that capsid is degraded by the ubiquitin-proteasome system. However, in contrast to that observed for other RNA and DNA viruses, dengue virus capsid degradation was not responsible for genome uncoating. Interestingly, we found that dengue virus genome release requires a nondegradative ubiquitination step. These results provide the first insights into dengue virus uncoating and present new opportunities for antiviral intervention.Fil: Byk, Laura Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Iglesias, Nestor Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: de Maio, Federico Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Gebhard, Leopoldo German. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Rossi, Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biomedicina de Buenos Aires - Instituto Partner de la Sociedad Max Planck; ArgentinaFil: Gamarnik, Andrea Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

Hyperspectral Chemical Imaging of Single Bacterial Cell Structure by Raman Spectroscopy and Machine Learning

6openopenBarzan, Giulia; Sacco, Alessio; Mandrile, Luisa; Giovannozzi, Andrea Mario; Portesi, Chiara; Rossi, Andrea MarioBarzan, Giulia; Sacco, Alessio; Mandrile, Luisa; Giovannozzi, Andrea Mario; Portesi, Chiara; Rossi, Andrea Mari

Advanced characterization of albumin adsorption on a chemically treated surface for osseointegration: An innovative experimental approach

Surface chemistry, charge, wettability, and roughness affect the adsorbed protein layer, influencing biocompatibility and functionality of implants. Material engineering seeks innovative, sensitive, and reliable characterization techniques for study the adsorbed proteins. These techniques must be suitable to be directly used on the surfaces of clinical interest. In this paper, the characterization of surfaces with topography and chemistry developed for osseointegration is performed by innovative surface analysis techniques to investigate the properties of adsorbed bovine serum albumin. Ti6Al4V alloy chemically treated with an oxidative process to obtain peculiar surface features (roughness and surface hydroxylation) was tested and compared with mirror-polished titanium. Albumin forms a continuous layer on both Ti surfaces when adsorbed from near physiological concentrations, as proved by Kelvin force probe microscopy. It was observed that the hydroxylation degree plays a pivotal role in determining the conformation of proteins after adsorption, where it strongly drives protein unfolding, as confirmed by Surface Enhanced Raman scattering, and in influencing the mechanism and chemical stability of protein-surface interactions, which was highlighted by zeta potential titration curves.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Elección de estudios CTIM y desequilibrios de género

A pesar de su éxito académico, las mujeres siguen poco representadas en los estudios CTIM, principalmente en las ingenierías y tecnologías. Desde un enfoque descriptivo-interpretativo, se realizó un estudio de caso múltiple para analizar la elección de estudios durante el bachillerato, ahondando en los este¬reotipos y la autoeficacia. El análisis se basó en 89 discursos recogidos en entrevistas en profundidad y grupos de discusión, correspondientes a alumnas y alumnos de bachillerato, su profesorado, sus madres y padres, y universitarias de CTIM, profundizando en la comprensión de los elementos individuales, académico-profesionales y contextuales que influyen en la elección de los estudios. Los datos señalan que la autoeficacia en CTIM declarada por las jóvenes fue siempre positiva, siendo muy similares los intereses y las motivacio¬nes del alumnado. Sin embargo, se observa una disparidad entre lo que ellas declaran y lo que finalmente deciden. Se propone una concepción dinámica de autoeficacia, con recomendaciones para diferentes actores y ámbitos de socialización orientados a construir nuevos modelos e identidades de las y los jóvenes

Competencia digital e innovación pedagógica: Desafíos y oportunidades

Digital competence continues to be a challenge for pedagogic practice and educational innovation, and the integration of ICTs in the teaching experience. This article presents the results of research on teaching practices related to digital competence. From a qualitative approach, a multiple case study was conducted in two schools, identifying facilitators and obstacles in the process of teaching acquisition of digital competence, and delving into the attitudes and use of ICTs according to a school's structure, strategy and culture. The results indicate that the complex process of acquisition of digital competence is the main difficulty of teachers related to the management of information, the didactic use of ICTs, the evaluation of digitally mediated activities and collaboration in virtual environments. The results also point to an image of isolation in professional development, hampering the exchange of experiences and meanings, and the perception of benefit and confidence in the use of ICTs. Teachers demand a training more consistent with their teaching needs. In relation to this, in-school project-based learning work has been recognized as a good practice. It was concluded that there is a need to reduce the gap between the desired digital competence and the actually acquired one by developing autonomous, collaborative, and prolonged training experiences that promote reflective practice and school innovation

Development of innovative antioxidant food packaging systems based on natural extracts from food industry waste and Moringa oleifera leaves

Active packaging that prolongs food shelf life, maintaining its quality and safety, is an increasing industrial demand, especially if integrated in a circular economy model. In this study, the fabrication and characterization of sustainable cellulose-based active packaging using food-industry waste and natural extracts as antioxidant agents was assessed. Grape marc, olive pomace and moringa leaf extracts obtained by supercritical fluid, antisolvent and maceration extraction in different solvents were compared for their antioxidant power and phenolic content. Grape and moringa macerates in acetone and methanol, as the most efficient and cost-effective extracts, were incorporated in the packaging as coatings or in-between layers. Both systems showed significant free-radical protection in vitro (antioxidant power 50%) and more than 50% prevention of ground beef lipid peroxidation over 16 days by indirect TBARS and direct in situ Raman microspectroscopy measurements. Therefore, these systems are promising for industrial applications and more sustainable farm-to-fork food production systems

Fabrication of flexible silicon nanowires by self-assembled metal assisted chemical etching for surface enhanced Raman spectroscopy

A homogenous array of flexible gold coated silicon nanowires was fabricated by the combination of nano spheres lithography and metal assisted chemical etching to obtain highly effective Surface Enhanced Raman Spectroscopy (SERS) substrates. 3D nanostructures with different aspect ratios and well-defined geometries were produced by adjusting the fabrication parameters in order to select the best configuration for SERS analysis. The optimum flexible nanowires with an aspect ratio of 1 : 10 can self-close driven by the microcapillary force under exposure to liquid and trap the molecules at their metallic coated ``fingertips'', thus generating hot spots with ultrahigh field enhancement. The performance of these SERS substrates was evaluated using melamine as the analyte probe with various concentrations from the millimolar to the picomolar range. Flexible gold coated SiNWs demonstrated high uniformity of the Raman signal over large area with a variability of only 10% and high sensitivity with a limit of detection of 3.20 x 10(-7) mg L-1 (picomolar) which promotes its application in several fields such food safety, diagnostic and pharmaceutical. Such an approach represents a low-cost alternative to the traditional nanofabrication processes to obtain well ordered silicon nanostructures, offering multiple degrees of freedom in the design of different geometries such as inter-wire distance, density of the wires on the surface as well as their length, thus showing a great potential for the fabrication of SERS substrates